Expert: John Shea - 6/19/2010

Question
Aboriginal australians, are they related to any existing human group in asia or south africa?

Answer
Genetic and fossil evidence suggests Aboriginal Australians are descended from African Homo sapiens populations who began dispersing into Asia along the Indian Ocean Coast after around 65,000 years ago.  Genetic variation (and to some extent, fossils) suggests there may have been at least two somewhat distinct "waves" of migration to Australia.  The first, probabably by more rugged-looking individuals following the coastline, the second by somewhat more gracile individuals.
For a good overview of this issue, see Steven Oppenheimer's, book, The Real Eve.
For detailed info on archaeology of Aboriginal Australia, try either Kamminga and Mulvaney Prehistory of Australia, or Harry Lourandos' Continent of Hunter-Gatherers.
(Sorry for delay in reply, am recovering from marathon bike ride!)
Cheers,
John Shea